The productivity and/or lifetime of certain late transition metal olefin polymerization catalysts are increased by carrying out the polymerization in the presence of selected silicon compounds.
Many types of olefin polymerization catalysts are known, and others are constantly being sought, due to the commercial importance of polyolefins. In the last few years interest in late transition metal olefin polymerization catalysts has been quite high, partially because of the discovery that they often can produce polyolefins which have unique structures, and/or they can copolymerize polar co-monomers.
One problem with some of these catalysts however is their relatively low polymer productivity, and/or their relatively short half lives in the polymerization, and/or their sensitivity to decomposition at elevated temperatures. Some or all of these factors are often interrelated. It has been discovered that the presence of certain silicon compounds during the polymerization often helps alleviate one or more of these problems.
WO9905189 (incorporated by reference herein for all purposes as if fully set forth) describes the copolymerization of polar (functional) olefins with ethylene using certain Ni catalysts. Among the polar olefins are a variety of silanes.
This invention concerns a process for the polymerization of olefins, comprising the step of contacting, under coordination polymerization conditions:
a monomer component comprising a polymerizable olefins;
an active polymerization catalyst comprising a Group 8, 9 or 10 (IUPAC) transition metal complex of a bidentate ligand; and
an organic silicon compound in which at least one atom of a Group 15 or 16 (IUPAC) element is bound directly to a silicon atom.
This invention also concerns an improved process for the polymerization of olefins, said process comprising the step of contacting, under coordination polymerization conditions:
a monomer component comprising a polymerizable olefins, and
an active polymerization catalyst comprising a Group 8, 9 or 10 transition metal complex of a bidentate ligand,
wherein the improvement comprises contacting said monomer component and active polymerization catalyst in the presence of an organic silicon compound in which at least one atom of a Group 15 or 16 element is bound directly to a silicon atom.
These and other features and advantages of the present invention will be more readily understood by those of ordinary skill in the art from a reading of the following detailed description. It is to be appreciated that certain features of the invention which are, for clarity, described below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination.